Warped sheet feeding mechanism



July 16, 1968 w. F. WARD ETAL WARPED SHEET FEEDING MECHANISM 4Sheets-Shem 1 Filed Jan. 12, 1966 A M A m m",

INVENTORS WILL MM F THOMS W/LL/AM 6'. .STALEY ATTORNEY BY Mam July 16,1968 w. F. WARD ETAL 3,392,973

WARPED SHEET FEEDING MECHANISM Filed Jan. 12, 1966 4 Sheets-Sheet 2INVENTORS W/LL/AM E WARD WILL/14M THOMS W/LL/AM C. 57211.5)

ATTORNEY W. F. WARD ETAL WARPED SHEET FEEDING MECHANISM July 16,1968

F iled Jan. 12, 1966 4 Sheets-Sheet 5 INVENTORS F WARD WILL IA F. 77%?ATTORNEY July 16, 1968 w. F. WARD ET AL 3,392,973

WARPED SHEET FEEDING MECHANISM Filed Jan. 12, 1966 4 Sheets-Sheet 4INVENTORS W/LL/AM 5 1464190 WILLIAM F THO/W5 WILL/AM C STALL Y ATTORNEYUnited States Patent 3,392,973 WARPED SHEET FEEDING MECHANISM William F.Ward, Hampstead, William F. Thoms, Baltimore, and William C. Staley,Towsou, Md., assignors to The Ward Die-Vise Company, Baltimore, Md., acorporation of Maryland Filed Jan. 12, 1966, Ser. No. 520,219 8 Claims.(Cl. 271-44) ABSTRACT OF THE DISCLOSURE A mechanism for bottom feedingstiff sheets from a pile is provided wherein pressure on the top of thepile for straightening the sheets is not required, whereby more sheetscan be added to the pile, the mechanism comprising structure including athreshold defining a feed opening along the bottom sheet of one side ofthe pile, shoes for positioning the bottom sheet along the opposite sideof the pile, fingers entering the named sides of the pile and urging thebottom sheet against the threshold and the shoes, and a reciprocatingbar for pushing the bottom sheet through the opening.

This invention relates generally to sheet feeding apparatus, and moreparticularly it pertains to a mechanism for forming a pack of sheets forbottom delivery.

Old machines which feed stiff corrugated board, cardboard, orfibreb-oard encountered trouble with warped sheets. A constant hold-downwas required on top of the pack to flatten it so only the bottom sheetwould be engaged and pass under a feed gate. One approach to the problemutilized a spring pusher pawl and buckling of the pack. Thereplenishment of the pack required the removal of the pack hold-downeach time and unless the machine was stopped a jam often resulted. Thespring pusher pawl, too, was troublesome because its height prevented astraight-in feed from the bed of the machine.

It is an object of this invention to overcome the stated problems byproviding a novel hold-down mechanism which operates by fingers enteringthe edge of the pack, and utilizing a pneumatic cylinder which re-cockswhen the finger approaches the bottom.

Another object of this invention is to provide means synchronous withthe pusher pawl so the pneumatic cylinder pressure is never releasedwhile a sheet is in a pushing cycle.

Yet another object of this invention is to provide near pressuremechanism for the pack utilizing edge entering fingers which renew theirgrip after each stroke of the pusher.

Still another object is to provide a marked sheet feeder mechanismhaving unobstructed pack loading and a low silhouette straight-in pusherpawl requiring no spring for bottom sheet engagement.

Other objects and attendant advantages of this invention will becomemore readily apparent and understood from the following detailedspecification and accompanying drawings in which:

FIG. 1 is a side elevation, somewhat diagrammatic, of a rotary diecutting and creasing machine using the improved warped sheet feederapparatus;

FIG. 2 is an enlarged top plan view of the feed area of the machine ofFIG. 1 with the pack removed and feed bar 16 displaced from beneath thefeeder assembly for clarity;

FIG. 3 is an enlarged top view of a shaft actuator assembly;

FIG. 4 is the side elevation of a shaft actuator assembly shown with thecam of the feed bar thereunder;

FIG. 5 is a side elevation of the rear pawl assembly;

3,392,973 Patented July 16, 1968 FIG. 6 is a plan sectional view of therear pawl assembly taken on the line 66 of FIG. 5;

FIG. 7 is a side elevation of the front hold down and gate assembly; and

FIG. 8 is a front elevation of the front hold down and gate assembly.

Referring now to the details of the drawings as shown in FIGS. 1 and 2,reference numeral 10 indicates generaly a rotary cutting and creasingmachine. This machine 10 may also be of any other type such as aprinting machine, folder, stuffer or the like requiring the feeding ofsheets. A rear table or table arms 12 extends from the machine 10 at theinput end and supports a fixed feeder assembly 14 in an adjustableposition, and a reciprocating feed bar 16 which sweeps under the latterand to the rear.

A sweep arm 18 on the machine 10 and linkage 20 stroke the feed bar 16back and forth on the table arms 12. A pair of right angled packalignment cheeks 22 are secured forward above the table arms 16 to across member 24 of the machine 10.

This cross member 24 also carries a pair of front hold down and gateassemblies 26. Between the pair of cheeks 22 at the sides and betweenthe front hold down and gate assembly 26 and fixed feeder assembly 14 atthe rear there is a pack area 28 in which a pack P of sheets S may beloaded.

The reciprocating feed bar 16 carries a ramp-like cam 30 near one endand also, intermediate the ends, a plurality of thin pusher pawls 32each less than the thickness of a sheet S in height.

The fixed feeder assembly 14 has a plurality of rear pawl assemblies 34each having a pecking finger 36 and strung on a pair of shafts 38 and40. One shaft 38 is merely a support rod, while the other shaft 40supports as well as actuates the rear pawl assemblies 34 throughoscillation. The oscillation is imparted to shaft 40 by means of a shaftactuator assembly 42 mounted at either end of the fixed feeder assembly14. This motion occurs each time the cam 30 is stroked under the shaftactuator 42. Also shown in FIGS. 1 and 2 are pack alignment springs 44which serve to urge the pack P forwardly as it is stacked in front ofthe feeder assembly 14.

The shaft actuator assembly 42 is shown in detail in FIGS. 3 and 4 andconsists of a cam follower 46 mounted on the end of a bar 48 which isattached to the shaft 40 through a pair of overtravel absorbing springs50. Each pass of the cam 30 causes the bar 48 to tilt and the shaft 40to oscillate.

As shown in FIGS. 5 and -6, the shaft 40 moves other bars 52, andisolating or bias springs 54, in turn, tend to move a pecking arm 56pivoted on shaft 40 in each pawl assembly 34 from the dotted position toa downward position shown in solid lines. Actually, a sharpened point 58on the end of the pecking finger 36 enters the edge of the pack P atsome intermediate point and moves down as far as the bias springs 54allow. The pecking finger 36 is biased by a compression coiled spring 60so as normally to extend radially outward somewhat with relation to arm56. A shoe 62 secured to each pawl assembly 34 positions the lowermostsheet S of the pack P in proper relation to the in-moving pusher panel32 of the feed bar 16 previously described.

The front hold down and gate assembly 26 consists of a pair of verticalslide members 64 which are provided with gear racks 66 and gearedtogether with a pair of intermediate gears 68 for simultaneous upward ordownward movement. A sharp pawl finger 70 is mounted on the lower end ofeach slide member 64. In the same vertical plane with the slide members64, a gate member 72 is provided which extends downwardly nearly to athin threshold plate 74 leaving a gap for a single sheet S from the packP to pass.

The pawl fingers 70 are urged from the elevated position shown to alower position (in phantom lines, FIG. 7) by a pneumatic cylinder 76which connects with one of the slide members 64. An upper limit switch78 and a lower limit switch 80 are also actuated by the pneumaticcylinder 76.

An electrically operated valve 82 as shown in FIG. 1 controls theintroduction of air pressure to pneumatic cylinder 76 and, in turn, thelimit switches 78 and 80 control the valve 82. A synchronizing switch 84is positioned adjacent to the sweep arm 18 of the machine 10, and itopens the electric circuit between the lower limit switch 80 and thevalve 82 whenever a stroke cycle is occurring. In this manner, a lowlimit command for the pneumatic cylinder 76 to recock or go to the topis never allowed to occur and release pressure on the pack P at suchtime.

It will be noted that the pawl fingers 70 enters the edge of pack P nearthe top thereof each time the pneumatic cylinder 76 restrokes upward. Intheir downward movement under urging by the cylinder 76, pressure isexerted by the fingers on the pack P in a constant bias.

The rear pawl assemblies 34 however peck or renew the engagement oftheir pecking fingers 36 with the pack P with each feed stroke of thefeed bar 16.

At all times, the pack area 28 is open and accessible for replenishmentof the pack P. Any warped sheets S are pressed down and flattened bothagainst threshold plate 74 and shoe '62 permitting perfect feeding ofthe sheets S one at a time without a miss-stroke.

Obviously many modifications and variations of the present invention arepossible in light of the above teachings. It is, therefore, to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. Mechanism for feeding stiff sheets from the bottom of a pack thereof,comprising, structure including a threshold member and gate means spacedtherefrom to form an opening along one side of said pack for the passageof the bottom sheet of said pack, reciprocating means positioned alongthe opposite side of said pack for pushing said bottom sheet throughsaid opening, shoe means for positioning said bottom sheet for saidpushing by said reciprocating means, and finger means for entering saidone side and said opposite side of said pack and urging said bottomsheet against said threshold member and said shoe means, whereby saidbottom sheet is flattened to facilitate pushing by said reciprocatingmeans and yet the top of said pack remains open for the addition of moreof said stiff sheets to said pack.

2. The mechanism of claim 1, and fluid pressure cylinder means having apiston operatively connected to said finger means along said one side ofsaid pack, with said piston maintaining the entrance engagement of saidlast-mentioned finger means with said pack during the successive feedingof a plurality of said stiff sheets from the bottom thereof.

3. The mechanism of claim 2 and control means for shifting said pistonand thereby said engagement of said finger with said one side of saidpack to a higher portion thereof.

4. The mechanism of claim 3 and additional control means for preventingsaid shifting during the pushing of said bottom sheet by saidreciprocating means.

#5. The mechanism of claim 4 and means for oscillating the finger meansalong said opposite side of said pack into and out of engagementtherewith in response to said pushing by said reciprocating means.

6. The mechanism of claim 1 and means for oscillating the finger meansalong said opposite side of said pack into and out of entranceengagement therewith in response to said pushing by said reciprocatingmeans.

7. The mechanism of claim 1 wherein said spring means biases said fingermeans along said opposite side of said pack into entering said pack.

8. The mechanism of claim 1 wherein said finger means along saidopposite side of said pack are pivotally mounted and cam means aremounted on said reciprocating means for pivoting said finger means outof entrance engagement with said pack during said pushing by saidreciprocating means.

References Cited UNITED STATES PATENTS 1,490,773 4/1924 Gunn 271-44EDWARD A. SROKA, Primary Examiner.

